The Manual of Antimicrobial Susceptibility Testing was developed to help clinical and public healthlaboratorians understand the principles and practices of antibiotic susceptibility testing. It closely follows the content and design of the CD-ROM released in 2002 by the CDC entitled Antimicrobial Susceptibility Testing - A Self-study Program authored by F. C. Tenover, J. F. Hindler, and E. Rosner. In addition to providing accurate susceptibility reports for guiding patient care, a major goal of this manual is to have laboratories from different hospitals, regions and nations follow exactly the same procedures and quality control practices.In this way susceptibility patterns from throughout the Americas can be reliably compared, facilitating recognition of emerging resistance and novel resistance patterns.

The target audience for the Manual of Antimicrobial Susceptibility Testing includes microbiologists in the laboratory who perform and interpret the results of antimicrobial susceptibility tests in clinical or public health laboratories. Readers who have experience working in a clinical microbiology laboratory will find the information in this manual to have direct application for their susceptibility testing methods. Laboratory directors should find this information useful as they design new procedures and update policies for susceptibility testing. This manual also could be a resource for senior students in medical technology or medical microbiology programs.

The major mechanisms of antibiotic resistance are explained. The background information in each chapter is designed to help the reader understand the principles and pitfalls of susceptibility testing methods. Emphasis is placed on disk diffusion testing because this method has proven to be accurate, reproducible, technically simple and relatively inexpensive. The importance of quality control and quality assurance is stressed so that laboratories and clinicians can be assured that their susceptibility reports are accurate.